Benazir, Radianta Triatmadja, Hasdinar Umar, Pakhrur Razi
Tsunamis remain a major coastal hazard, requiring mitigation strategies that are both effective and sustainable. This study investigates the performance of coastal vegetation as a form of green infrastructure for tsunami attenuation through controlled laboratory experiments using dam-break-generated bores. The novelty of this study lies in the integrated evaluation of vegetation density, planting arrangement, and gap configuration within a single experimental framework, with direct implications for practical coastal planning. The results show that vegetation significantly reduces wave height, with high-density configurations achieving reductions of approximately 40–60%, compared to only 20–40% in lower-density cases. Staggered planting patterns further enhance attenuation, producing an additional 10–20% reduction relative to aligned layouts by disrupting preferential flow paths. Under optimal configurations, wave height reduction exceeds 50–60%, with peak attenuation reaching up to 85–92% under low incoming wave conditions. In contrast, open gaps reduce protective performance, with straight-line gaps allowing higher wave transmission, while serpentine configurations improve attenuation by 5–10% by redirecting flow and increasing energy dissipation. Overall, the findings demonstrate that vegetation effectiveness depends not only on density but also on spatial configuration and gap design. The study provides quantitative guidance for optimizing coastal forest design, highlighting the importance of integrating density, arrangement, and pathway planning to enhance the role of nature-based solutions in tsunami risk reduction. © The Author(s), under exclusive licence to Springer Nature B.V. 2026.
Civil and Environmental Engineering Department, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika, Kampus No.2, Yogyakarta, 55281, Indonesia; Coastal Engineering Department, Hasanuddin University, Makassar, Indonesia; Physics Department, Universitas Negeri Padang, Padang, Indonesia
